Practice golf club

ABSTRACT

The invention consists in providing in the shaft of a golf club a spring supported weight, preferably a dry battery, which is slidable in said shaft under the action of centrifugal force and against the action of said spring attached thereto to cause said weight to engage an electric contact in the circuit of a lamp bulb mounted in the club head to cause said lamp to light up during the swinging of said club. The spring to which the battery is attached is carried by a rod which may be axially adjusted within a guide sleeve in the shaft of the club by rotating an adjusting knob mounted on the end of said shaft by means of a friction plug and fixed to a screw connected to axially displace said rod when said knob is rotated. The electrical contact is mounted on an insulating plug in said shaft at a point spaced from the battery.

D United States Patent 1151 3,677,553 Moore [4 July 18, 1972 [54] PRACTICE GOLF CLUB 1,471,794 /1923 Leven ..273/193 R x [72] Inventor. $513111 alggore, l1 Stanmore H111, Primary Examiner George J Marlo Attorney-Holc0rnbe, Wetherill 8'1. Brisebois [22] Filed: Sept. 14, 1970 211 Appl. No.: 71,957 [57] ABSTRACT The invention consists in providing in the shaft of a golf club a spring supported weight, preferably a dry battery, which is Foreign Application Prim-"y Dam slidable in said shaft under the action of centrifugal force and 1969 Great Britain against the action of said spring attached thereto to cause said weight to engage an electric contact in the circuit of a lamp [52] U.S. Cl ...273/186 A, 273/81 A, 273/ bulb mounted in the dub head cause i lamp to light up [51] Int. Cl. ..A63b 69/36 during the Swinging of Said club The spring to which the [58] Fleld 0f Search ..273/i86, 193, 194, 183, 26 tery i attached i carried by a rod which may be axially justed within a guide sleeve in the shaft of the club by rotating [56] References C'ted an adjusting knob mounted on the end of said shaft by means UNITED STATES PATENTS of a friction plug and fixed to a screw connected to axially displace said rod when said knob is rotated. The electrical con- Aitken A tact is mounted on an insulating in said shaft at a point 3,106,403 10/1963 Kirkman ..273/186 A spaced f h battery 3,380,305 4/1968 Charell ..273/186 A X 2,080,608 5/1937 Hannaford ..273/1 83 D 5 Claims, 3 Drawing Figures Patented July 18, 1972 3,677,553

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Patentd July 18, 1972 2 Sheets-Sheet 2 PRACTICE GOLF CLUB This invention relates to a golf club, intended more particularly for practice purposes incorporating means for enabling the user, or coach instructing the user, to check the correctness or otherwise of the user's swing.

In its broadest aspect the invention consists in providing in the shaft of a golf club means actuated under the action of centrifugal force, during swinging of the club, to close contacts to complete an electric circuit containing a lamp mounted in the head of the club.

In order that the invention may be more clearly understood one particular embodiment thereof will now be described, by way of example, with reference to the accompanying drawings in which:

FIG. I is a part axial sectional view of a device, according to the invention, adapted to be housed in the hollow shaft of a golf club,

FIG. 2 is a side elevational view of the upper end of said device, and

FIG. 3 is a part longitudinal sectional view of the practice golf club according to the invention.

Referring to these drawings the device comprises an upper head member 3 to which is attached a flexible, preferably rubber, plug member 4 adapted to fit frictionally into the outer end of the handle portion of the shaft of a golf club. Coaxial with said plug member is an externally screw threaded shank 5 on which is screwed a guide sleeve 6 in which is slidably mounted an axially adjustable member in the form of a rod 7. The rod 7 is provided at its upper end with an internally screw threaded axial bore into which is screwed a screw 8 which passes coaxially through the shank 5, plug member 4 and head member 3 and has fixed at its outer end an adjusting knob 9. Rotation of said knob 9 causes axial movement of said rod 7 in the guide sleeve 6 for the purpose hereinafter described.

The guide sleeve 6 is provided with axially extending slots 6a in which slide guide ribs or strips 10 integral with or fixed on the rod 7, whereby said rod is guided axially relative to said guide sleeve while relative rotary movement between the rod 7 and guide sleeve 6 is prevented.

Into the lower or outer end of said rod 7 is screwed an externally screw threaded axial boss portion 11a formed on one end of a tubular member 11 to the opposite end of which one end ofa helical spring 12 is attached by a head-less screw member 13. The opposite end of said helical spring 13 is attached to a holder 14 for a dry battery 15 and said helical spring is housed in an elongated tubular member 16 which at one of its ends abuts the rod 7 and the other end abuts the battery carrying holder 14.

As above described the device illustrated in FIG. 1 is slidably fitted into the upper or handle portion 18 of the shaft 19 of a golf club and secured therein by said plug member 4. Also mounted in the hollow shaft of the golf club intermediate its ends and spaced from the contact terminal 17 of the battery 15, is a fixed electric contact 20 which is wired, by conductor wires 21 passing down the shaft 19 of the club, to an electric bulb 22 mounted in the upper face of the head 23 of the golf club, the shaft itself forming the earth of an electric circuit containing the electric bulb. The contact 20 is mounted in an insulating plug 24 fitted in a sleeve 25 fixed in the shaft of the club adjacent to the club head 23.

The device according to the invention operates as follows:

When a golfer swings the golf club the weight of the battery 15 and its supporting holder 14 will, under the action of centrifugal force, move down the hollow shaft of the club towards the club head against the action of spring 12 and come into contact with said fixed contact therein and thus close the electric circuit containing the light bulb 22 and cause the bulb in the head of the club to light up. Thus the golfer, and/or his coach, will have a visual indication of the exact path or are taken by the club head during the swing and thus enable him to check whether the club head is being swung correctly, i.e.,

whether the club head moves through the correct arc. Furthermore, as the closing of the electrical contacts is dependent upon centrifugal force the device enables the golfer, and/or his coach, to see the precise points along the arc of the swing at which the light comes on and goes off, thereby indicating not only whether the arc of the swing is correct but also whether the club head reaches its maximum speed during the correct period of the swing.

It will be appreciated that the power" of the swing will vary with different individuals so that it will be necessary to adjust the initial position of the battery 15 relative to the contact 20 whereby a greater or lesser degree of centrifugal force will be required to cause the electric contacts to be closed dependent upon the person using the club. As will be understood the greater the distance between the battery 15 and the contact 20 the greater the *power" will be needed to cause the electric circuit to be closed during the swinging of the club. The adjustment of the initial position of the battery is effected by rotation of the knob 9 which causes axial movement of the rod 7 in one or other direction and thereby the desired variation in the initial position of the battery relative to the contact 20.

It must be understood that the invention is not limited to the particular embodiment herein described and illustrated but modifications can be made without departing from the scope of the invention as defined in the appended claims.

I claim:

1. A practice golf club comprising a hollow shaft, a club head fixed to one end of said shaft, an axially adjustable member within said shaft, a dry electrical battery housed in said shaft and axially slidable therein, a helical spring attached at one end to said battery and at the other end to said adjustable member, so that when centrifugal force is applied to said battery by swinging of said club said sliding movement of said battery away from said adjustable member is resisted by said spring, an electrical circuit in said club containing a light bulb mounted in said club head, a contact in said circuit positioned to be engaged by said battery to close said circuit when said battery is moved away from said adjustable member, and means accessible from the end of said shaft remote from said head for adjusting the position of said adjustable member.

2. A practice golf club according to claim I, wherein said axially adjustable member is slidably mounted in a guide sleeve and said means for adjusting the position of said adjustable member comprises a screw screwed into said adjustable member and rotatable by an adjusting knob at the outer end of the handle portion of the shaft of the club, means for preventing axial movement of said screw and means for preventing relative rotation between said adjustable member and said guide sleeve.

3. A practice golf club according to claim 2, wherein said guide sleeve is screwed onto a shank portion of a head member to which is attached a flexible plug member fitted frictionally into the outer end of the handle portion of the shaft of the club, said screw passing coaxially through said shank portion.

4. A practice golf club according to claim 1, wherein said spring is housed in an elongated tubular member which at one of its ends abuts said axially adjustable member and at its other end abuts a holder for holding said dry battery.

5. A practice golf club according to claim 4, wherein said contact is mounted in an insulating plug fitted into a sleeve positioned in the shaft of the club adjacent to the club head. 

1. A practice golf club comprising a hollow shaft, a club head fixed to one end of said shaft, an axially adjustable member within said shaft, a dry electrical battery housed in said shaft and axially slidable therein, a helical spring attached at one end to said battery and at the other end to said adjustable member, so that when centrifugal force is applied to said battery by swinging of said club said sliding movement of said battery away from said adjustable member is resisted by said spring, an electrical circuit in said club containing a light bulb mounted in said club head, a contact in said circuit positioned to be engaged by said battery to close said circuit when said battery is moved away from said adjustable member, and means accessible from the end of said shaft remote from said head for adjusting the position of said adjustable member.
 2. A practice golf club according to claim 1, wherein said axially adjustable member is slidably mounted in a guide sleeve and said means for adjusting the position of said adjustable member comprises a screw screwed intO said adjustable member and rotatable by an adjusting knob at the outer end of the handle portion of the shaft of the club, means for preventing axial movement of said screw and means for preventing relative rotation between said adjustable member and said guide sleeve.
 3. A practice golf club according to claim 2, wherein said guide sleeve is screwed onto a shank portion of a head member to which is attached a flexible plug member fitted frictionally into the outer end of the handle portion of the shaft of the club, said screw passing coaxially through said shank portion.
 4. A practice golf club according to claim 1, wherein said spring is housed in an elongated tubular member which at one of its ends abuts said axially adjustable member and at its other end abuts a holder for holding said dry battery.
 5. A practice golf club according to claim 4, wherein said contact is mounted in an insulating plug fitted into a sleeve positioned in the shaft of the club adjacent to the club head. 